In electronic commerce sites, a product page including a description sentence for a product in which, for example, a feature of the product that is a presentation target is described is presented to users. Automatically attaching a tag to a phrase indicating the feature of the product included in the description sentence for the product and generating corpus data has been conventionally attempted. According to such corpus data, structured data regarding the product can be automatically generated through machine processing based on the tag.
For example, a technology described in Patent Literature 1 is known as a technology for automatically attaching a tag to a natural sentence such as a description sentence for a product. A sentence processing device that extracts a general-purpose unique representation and a semantic role word from an input document by referring to dictionary data, estimates a sentence structure of the input document based on the general-purpose unique representation and the semantic role word, and attaches a meaning tag to the input document according to a rule defined for a sentence structure in advance is described in Patent Literature 1.